The invention concerns a dual belt press of the type in which a material is compressed between a pair of moving belts. The belts are supported on rolls which are carried by guide chains.
Guide chains of this type are known. They primarily serve to guide the parallel rolls disposed between one press belt of the dual belt press and the associated press plate. The forces appearing in the press zone between the moving press belt and the rolls may be very large and thus the rolls are entrained in this press zone by the moving belt. It is necessary that the rolls be maintained as parallel to each other as possible and exactly perpendicular to the direction of travel of the belt, in order to prevent the rolls from slipping out of the press zone. Arrangements have been proposed (e.g., see German Published Application No. 34 32 548-C2), wherein the parallel rolls in the press zone are somewhat freely carried by the guide chains, which is achieved in that the studs guiding the rolls are carried with clearance in the lateral chain link plates. In an arrangement of this type, care must be taken that there occurs no skewing of the rolls in the press zone. Consequently, relatively stable chain links are provided for the guidance of the roll studs, which links travel in separate guides.
The roll guides according to German Published Application No. 31 40 548-C1 also comprise stable chain links. Roll bearings are located in an area offset relative to the plane of the chains, whereby it is possible to arrange several rolls with smaller diameters adjacent to each other, without having to dimension the chain links narrower.
However, all of the conventional forms of the guide chains exhibit the disadvantage that the chain links have an unavoidable inherent play due to manufacturing tolerances, which in actual operation may be enlarged further by the forces generated. A stable lateral guidance of the rolls in the press zone thus cannot be assured with the known configurations. It is the object of the invention to eliminate this problem.